Stowage Space Clearances
A tire expands as the fabric stretches during service. It also expands on account of heat generated during ground operations. It keeps spinning (further enlargement occurs due to centrifugal force of spinning) within the stowage space immediately after retraction. Stowage space within an aircraft should be of the minimum volume occupied by the retracted undercarriage with some clearance to avoid any interference that may occur. Enough cavity space should be inside the aircraft structure to accommodate tire expansions. Stowage space is dictated by the articulated mechanism for retraction from its unloaded free position. Semi-empirical relations govern the clearance gap to accommodate retraction. As mentioned previously, this book assumes that aircraft designers are in a position to offer proper stowage space with adequate clearances. This book does not discuss stowage-space computation. For thin-wing combat aircraft, stowage must be within the tightly packed fuselage, where space is limited.
Unless there is a breakthrough innovation (typically associated with unconventional new designs beyond the scope of this book) on retraction kinematics, the state-of-the-art undercarriage design has been established to maximize compactness. This book addresses articulation in its simplest form. The author recommends using CAD animation to check retraction kinematics and storage space during the second-term coursework.